Cutting machine



Mm 19, 1940. MA T, 2,193,878

CUTTING MACHINE Filed Feb. 4, 1938 4 Sheets-Sheet 1 ATTORNEYS March 19,1940.

W. L. MARTIN CUTTING MACHINE Filed Feb. 4, 1938 4 Sheets-Sheet 2INVENTOR ATTORN EYD March 19, 1940. w. MARTIN CUTTING MACHINE" FiledFeb. 4, 193 s 4 Sheets-Sheet 4 YINVENTIOR ATTORNEYS Patented Mar. 19,1940 UNITED STATES PATENT OFFICE CUTTING MACHINE Application February 4,1938, Serial No. 188,760

8 Claims.

This invention relates to cutting machines for cutting out designs andthe like from sheet like material.

The principal object of my invention is the provision of a relativelysmall, compact portable cutting machine adapted to be moved over thesurface of the work being cut and which is exceptionally quiet inoperation.

A further object of the invention is to provide a cutting machine inwhich the movement of the stripper foot is independent of the movementof the cutter and to the path created by the cutter whereby the cuttercan be operated in opposite directions, that is both forwardly andrearwardly.

A further object is to provide a cutting machine having a reciprocatingcutting blade wherein means is provided for controlling the length ofthe cutting stroke to thus maintain the blade in contact with the Workthroughout the cutting operation.

A further object is to provide a cutting machine wherein the weight ofthe machine is adjacent the cutter bar whereby the machine is evenlybalanced thus permitting the cutting blade to cut rapidly through thickmaterials.

A further object is the provision of resilient means connected to thecutter bar for holding the cutting blade in vertical alignment with thework for eliminating and/or minimizing all vibrational stresses andstrains incidental to the cutting operations.

Another object is to provide a stripper foot carried independently ofthe tool holder and adapted to move around the same axis as the tool 3.;holder.

Another object is to provide a stripper foot which is adjustably mountedindependently of the tool holder and is adapted to be positionedslightly out of engagement with the surface of the work whereby the endthereof serves to clean the blade at the termination of each upstrokethereof,

A further object is to provide a removable base member for supportingthe cutting machine in position on the work and which permits the operator to observe the action of the cutting tool from the front, rear orsides of the machine while the same is travelling over the work. 30Another object is the provision of formed base and bracket members sopositioned that the cutting machine may be tilted at angles ofapproximately 45 degrees whereby the cutting tool is relieved of strainand freed from engagement 5 with the work thus facilitating access tothe tool holder and associated parts to permit of adjustment orreplacement thereof.

Another object is to provide an electromagnetic vibrator for actuatingthe cutter bar and blade wherein means is provided for the adjustmentand control of the thrust of the electromagnet.

Other and more specific objects and advantages will be apparent as thefollowing specification is considered in connection with theaccompanying drawings, wherein:

Figure 1 is a perspective view of the assembled cutting machine;

Figure 2 is a partial section on line 22 of Figure 4;

Figure 3 is a section on the line 33 of Figure 4;

Figure 4 is a bottom view of the machine;

Figure 5 is a side elevation of the machine;

Figure 6 is an enlarged section through the cutter assembly andelectromagnet;

Figure 7 is an enlarged section on line ll of Figure 6;

Figure 8 is an enlarged section on line 88 of Figure 7;

Figure 9 is a rear View of the machine with the cover removed;

Figure 10 is a diagrammatic circuit for direct current; and

Figure 11 is a diagrammatic circuit for alternating current.

Referring more particularly to the drawings wherein like referencenumerals refer to similar parts throughout the several views, numeral Idenotes an integral, substantially square, supporting casting havingfront, side and rear Walls 2, 3 and 4, respectively, which casting ismounted upon and spaced a substantial distance above a base member 5.The base is comprised of a substantially U-shaped resilient metal runner6, preferably substantially circular in cross section, the relativelystraight parallel side portions I0 thereof being bent upwardly at theirends to form two vertical leg portions 1 which are fixedly but removablypositioned within bores or recesses 9 in two downwardly depending lugsor bosses 8, integrally formed in the corners of the rear wall 4 of thecasting, by means of screws 9. The curved or bowed forward portion ll ofthe runner 6, extends slightly beyond the front wall 2 of the casting.Thus, the curved undersides of the runner are adapted to rest andsupport the casting and machine on the surface of the work being cut andwill slide thereover in a manner hereinafter described.

A substantially rectangular body portion [2 extending inwardly from therear wall 4 of the supporting casting is provided with a web or wall Itto which a laminated U-shaped core M is rigidly secured by suitablemeans, such as rivets E5. The core M has spaced vertical arms It, theupper ends of which are beveled to provide converging inner faces l'l.Substantially U-shaped, outwardly extending, upper and lower brackets i8and iii are secured to the sides of the core arms it at the upper andlower ends 253 and 2! respectively, by suitable means, such as rivets22. The lower ends 2 2 of an upstanding inverted U-shaped upper metalstrap 23, extending a suitable distance above the upper ends 20 of thecore arms, are secured to the upper brackets M3 by rivets or the like25, and the upper ends 2'1 of a downwardly extending U-shaped lowermetal strap 26, extending a suitable distance below the lower ends 26 ofthe core arms, are likewise secured to lower brackets Hi by rivets orthe like 28. An upper flat steel leaf spring 25 is provided with blocks353 at its ends for adjustably securing the leaf spring to the sides ofthe upper strap by means of threaded bolts or the like 3!. The sides ofthe lower U-shaped strap 25 are likewise adjustably secured by means ofthreaded bolts 32 to the blocks Ed on the ends of a lower similarlyformed lower leaf spring 33, for a purpose to be presently described.Thus it will be noted that the upper and lower straps and leaf springsare positioned above and below and extend across the ends of theU-shaped laminated core M,

An inverted U-shaped clamping plate 55 fits over and is rigidly attachedby screws iii to the front and rear faces of a Wedge shaped armature orcore 36 which extends or seats within the beveled portions H on theupper end of the Ushaped laminated core M. Thus, the upper end of theclamping plate 35 is positioned beneath the upper lead spring 29 and ispreferably fixedly secured by rivets or the like 39 to a relativelynarrow channel plate 3%? on the top face of the said leaf spring,whereby the leaf spring will be caused to vibrate or flex when the wedgeshaped armature 3b reciprocates, as hereinafter described in detail. Anoutwardly extending supporting bracket ib, having upper and lowerapertured ears thereon, is secured to the front face 42 of the clampingplate by the screws Ell. An outwardly extending supporting bracket clipM, having an aperture 45 in the outer end thereof, is positioned abovethe lower leaf spring 33 and fixedly secured by rivets M to a channelplate 48 on the under side of the said leaf spring, whereby the bracketand spring will be caused to vibrate or reciprocate in a similar mannerto the corresponding upper bracket and spring described above.

A tubular sleeve d8 extends through the apertured ears M and aperture 45of the upper and lower supporting brackets 4-9 and it respectively, andtwo spacers or sleeves d8 are mounted be tween the said apertured earsll and bracket clip M. The sleeves or spacers in addition to encasingand protecting the sleeve 58 serve to brace and support the bracket earsM and bracket Al in position. The tubular sleeve M3 is retained inposition in the spacers and brackets by means of lock nuts 52 mounted ona threaded portion 5% of the sleeve extending above the upper bracketear H and a threaded section below the lower bracket it, which nuts abutand clamp the sleeve against the brackets. A tubular cutter bar orplunger shaft 53 is loosely sleeved within the tubular sleeve 33 andheld in position therein by two nuts or the like 54 threaded on theupper end thereof in abutting relation with the upper end 50 of thetubular sleeve 58. The lower end of the cutter bar extends through anapertured ear 5b of a substantially L-shaped bracket 55 which is securedto the front face 58 of core Hi by the screws i5. A blade carrier 8% isfixedly attached to the extreme lower end of the cutter bar 53 by a pinill whereby the blade carrier and cutter bar turn about an axisextending in the direction of reciprocation of the tubular sleeve it, ina manner hereinafter described. A vertical slot 62 is provided in theblade carrier for the reception of a blade =33 which is adjustably heldin position therein by a set screw 54, whereby the blade is offsetlaterally with respect to the swivel axis about which the cutter barturns in sleeve M3. The preferred form of blade has its front and rearedges ground at the lower end so that this end of the blade tapers to apoint and the side faces thereof taper to front and rear downwardlyconverging cutting edges, the cutter blade being positioned with itscutting edges in a plane disposed radially with respect to the swivelaxis, so that the blade will readily follow the direction of the cutterbar and supporting frame. In some instances where heavy duty materials,such as plywood and the like are being cut it may be desirable toutilize a sawtooth blade, not shown, in place of the above describeddouble cutting edge blade.

A knurled disc 65 is rotatably mounted, by means of a series ofvertically arranged needle roller bearings iii, on a relatively shortsleeve or hearing race 58 which is suitably secured to and is suspended.from the bracket ear 555. Thus, as the bearings 55'! engage with thebore 63 of the disc, the disc is adapted to freely rotate about thevertical axis of the sleeves t8 and dd, respectively, for a purposehereinafter explained. A stripper foot comprised of two relatively finestraight wires 55 extends through two apertures it in the blade carrierMl on either side of the slot 62 therein, and the upper ends thereofrigidly but adjustably secured in two apertures H in the disc flange byset screws or the like '62. The lower ends of the stripper foot wires 59are looped and flattened, as at i753 to form two relatively flat memberswhich flattened portions are spaced a slight distance above the surfaceof the material being cut and through or between which the cutter blade63 projects and reciprocates during the cutting operation to bepresently described. The machine can be operated in both directions,that is forwardly and then rearwardly due to the fact that the stripperfoot is fixedly supported with respect to the reciprocating cutter andthe looped and flattened ends 73 thereon are spaced above the materialand therefore does not engage the surface of the material and thusfollow in the groove or cut created by cutter blade. Consequently thecutter blade may be moved forwardly by proper manual. manipulation of:the machine, to cause one cutting edge to operate on the material andthen, after a slight turning movement of the .iachine, the latter may bemoved rearwardly, or in a direction substantially opposite to theforward movement, thus causing the same cutting edge of the blade to acton the material. is not possible with prior devices in which the presserfoot engages in the roove or cut made by the cutter.

A threaded adjusting screw 'M extends through a centrally locatedthreaded aperture it in the upper inverted U-shaped bracket 23 and isprovided on its lower end with a spring engaging collar I6 which abutsthe upper end of an upstanding coil spring 'II Seated on the channelplate 38 connected to the upper face of the leaf spring 29. The upperend of the screw I4 is knurled, as at '18 for convenient verticaladjustment of the same to increase or decrease the tension of coilspring 1! thereby controlling the amount of pressure of the latter onthe leaf spring. A knurled lock nut I9 is threaded on the adjustingscrew and serves to lock the screw and coil spring in any set positionin order to maintain the desired amount of pressure on the flat leafspring 29 for a purpose hereinafter described. The lowermost U-shapedstrap 26, previously referred to, is likewise provided with 2.preferably centrally located threaded aperture 80, through which athreaded adjusting screw 8| is adapted to upwardly extend. Fixedlymounted on the upper end of the screw 8| is a spring engaging collar 82for engagement with the lower end of an upstanding coil spring 83. Theupper end of this spring seats against the channel plate 46 connected tothe underside of the'lower flat leaf spring 33, and a nut 84 on theouter end of the screw serves to lock the screw and to permit ofvertical adjustment of the same in order to control the tension of thespring and govern the pressure acting upon the leaf spring.

It will be noted that the pitch of the two topmost convolutions of coilspring 83 are of much wider pitch than five lowermost convolutions. Thepurpose of this is to have these springs correspond in loadcharacteristics to the pulling power or pull characteristics of themagnet or coil I4, for the purpose of eliminating the whipping orslapping action which would otherwise occur at the end of the stroke ofarmature 36.

As the armature or core 36 approaches the end of its downward stroke andthe pull of the laminated core or pole piece I4 is therefore increased,the lower convolutions of springs 83 offer correspondingly increasedopposition or cushioning action to this downward movement of thearmature and will finally stop the same entirely as the faces of thearmature and pole pieces meet. This eliminates the objectionable noisecreated when two pieces of metal are slapped together.

In the operation of the machine, the U-shaped core I4 is intermittentlyenergized, drawing the wedge shaped core or armature 36 into engagementwith the converging inner faces Il thereof, and upon deenergization ofthe core I4, the armature is moved upwardly by the flexing action of theupper and lower flat leaf springs 29 and 33. As the cutter bar 53 isfixedly mounted on the wedge shaped armature 36, the movement of thelatter. through intermittent energization of the core I4. also resultsin the cutter bar being reciprocated whereby the cutter blade 63 cutsthrough the material over which the machine is moved by the operator whograsps knobs or handles 90 extending laterally from the forward end ofthe side walls 3 of the casting, as will hereinafter be described indetail.

The core I 4 is energized by means of coils 85 which are wound about thespaced vertical arms I6 of the core. The coils 85 receive electriccurrent through an extension cord 86, extending through an apertureddownwardly depending lug 81 on the underside of rear casting wall 4,which is connected to the coils through a manually operated switch 88positioned in a side wall of the casting, and a wire 89.

It is usually preferable to provide means adapting the device to beoperated either by direct or alternating current. To this end, means isprovided for automatically interrupting the current through the coilsduring the downward movement of the armature by means of a circuitbreaker, which includes a switch mounted on brackets 9| secured to therear faces 92 of the upper brackets I8. The switch consists of a rigidconductor screw 93 and a spring conductor element 94 secured at one endto one of the brackets 9| b-y rivets 95, and the conductor elementsbeing provided with contact points 96 and 97. The spring conductorelement 94 is provided with a vibrator spring 98 which is adapted to beengage by a vertical screw 99 carried by a bracket I secured to thearmature whereupon the downward movement of the armature causes thescrew to push the vibrator spring 98 downwardly to separate the contactpoints 96 and 91. The conductor elements 93 and 94 are connected to thecoils 85 by wires IM and I02. When the extension cord 86 is plugged intoa direct current line, the circuit through the coils 85 is broken eachtime the armature 36 is pulled into engagement with the core I I and thecircuit is re-established during the upward movement of the armature. Acondenser I03 is preferably connected across the contact points 96 and91. A resistance coil 91' is connected across the parts 9! and 98 toallow the voltage, built up at the instant of breaking, to bleed off,or, in other words, to cut down the high peak. The aforesaid directcurrent circuit is shown diagrammatically in Figure 10.

When the device is used on an alternating line, all that is necessary isto adjust the screw 99 upwardly a sumcient distance to clear the springvibrator spring arm 98 of the circuit breaker, as will be apparent byreference to the alternating current diagram shown in Figure 11.

Two light sockets I04 of conventional type are positioned in integralears I preferably formed on the forward wall 2 of the supporting castingI for the reception of suitable lamp globes I06. preferably of the sixto eight volt type. Thus the bulbs extend downwardly into the castingand are disposed on either side of the cutter blade carrier adjacent thelower end thereof, whereby the surface of the work is illuminated in anobvious manner. The lamp sockets I04 are connected to the inductioncoils 85 and the manually operated switch 88 by wires I Ill and I08, asshown in the diagrammatic circuit in Figure 10.

During the operation of the machine, the cutter unit is moved in anydirection over the material M being cut, which may be one or more layersof sheet material such as cardboard, paper, ply wood, or the like, anddue to the blade carrier being fixedly positioned on the lower end ofthe cutter bar 53, the carrier and blade will swing to a position wherethe blade is trailing the cutter bar as the latter is rapidlyreciprocated in the aforementioned manner. The blade may thus be causedto follow an irregular line on the work being cut by sliding the unit onthe material. The front wall 2 of the supporting casting is recessed asat I08, to provide a clear view of the cutting blade assembly as themachine is moved over the work, as shown in Figure 1.

By adjusting the upper and lower adjusting screws 14 and BI,respectively, the tension of the coil springs I? and acting on the upperand lower flat leaf springs 23% and respectively is increased ordecreased thus controlling the amount of of the said leaf spring on theWedge shaped. armature and core i ilfiien the on the leaf spring isdecreased, in the aforesaid mann r, the space or gap between the wedgeshaped iature and converging sea g faces ill of the core is thusincreased as the armature will move or adjust itself upwardly. Thereforeit follows, that when the space or gap between the core and armature isincreased and the core intermittently energized, the armature will becaused to move through a glflter distance befo e the seating faces ofthe core. T s results inthe reciprocal tory stroke of cutter bladecarrier and blade being increased to cut through. a thicker or 1, or forother purpose If decake of the cutter bar and blade 1 cued byELdjU.-Stll1t of the adjusting screws and increasing lie tension of thecoil spj gs whereby the will travel a shorter distance betweencontacting foes il of the core it. Regulation of the blade stroke in theabove manner the blade embedded in and pre uts the same from jumpingaway from or leav' the work, thus e the sity of providing a guide forthe blade. As the foot are fixedly secured in the sable butnon-reciprocable disc t5 and the flattened lower portions is of thestripper foot termir. ht distance above the plane the cutterreciprocatcs there- 'h and on the upstroke of the blade, the 'iai willbe lifted upwardly into engagement the lower: flattened ends of thestripper foot stripped therefrom in an obvious manner. Thus it will benoted that as the stripper foot is not supported on the work, there isno weight on. the latter at any time, and consequently no danger ofmarking or marring soft material.

Tire weight of the machine is adjacent or approx ate to vertical axis ofthe cutter ti. cby 'ng the cutter to r ciprocate rapidly and withthrough rela thief: aterials thus evenly balancing the the surface ofthe worn.

' leaf springs on the upper and lower armature and core members serve nthe blade carrier and blade in vertithroughout the cutting operation,and by ad listing the side screws 32 on the u per spring 532? thearmature may be ad, laterally to sing the same into all out with tileconver seating faces ii of the core, so that the gap or spacetherebetween may adjusted to shorten the stroke of the armature with .treduction of the noise produced by between. the armature and core.actuating mechanism is preferably enclosed by cover lul which rests uponthe top of the supporting casting l and is secured in 65 pl ice thwecnby suitable such as screws lid.

A substantially U-shaped bracket Hi is mounted in apertures H2 in therear wall of the su acting casting and extends laterally permits themachine to be rearwardly to an angle of approximately ive degrees whenthe operator desires to e cutting blade from the work to replacement oradjustment of the and associated parts. This bracket or- I bladerangement also serves to relieve the blade of undue stresses and strainswhich otherwise would be caused were the machine to be left in normalupright position with the blade imbedded in the work when the cuttingoperation is temporarily discontinued.

Due to the resiliency of the metal stool: from which the base 5 is made,the construction and point of attachment of the runner part 5 thereof tothe frame, it is possible to manually move the stripper foot downwardlyinto engage- 1 with the work, This sometimes becomes advisable in thecutting of hard fibrous material or be. 3, if the mater e. has atendency to rise or be pulled. upwardly unduly due to the action of thecutter blade on its up stroke, when the ads the roughened edges alongthe line of out. This movement of the stripper foot down upon the work,to hold the latter to the work table, is accomplished. by the operatorpressdownwa dly on the handles (it, thus causing 1e cutter frame and thestripper foot to move fiwarcll relatively to the resilient runner partIt will apparent that the present invention provides a simple, rugged,compact and highly nit for cutting irregular designs and .r in varioussheet materials by guiding the e over the surface of the work, with. thecylindrical resilient base runner riding y thereover and smoothing orflattening the in advance of the cutter blade assembly the machine ismoved in a forward or sidewise direction.

Furthermore, it is to be understood that the ticular form of apparatusshown and debed, is presented for purposes of illustration that variousmodifications of said apparatus can be without departing from my inven-1, defined in the appended claims.

vving thus described my invention what I claim is:

1. A cutter of the character described comprising a supporting framehaving a base attached thereto and adapted to slide on material being ar cut, power means on said frame, a plunger bar fixedly and rotatablysupported on said power means and reciprocated thereby, a tool holderfixedly secured to the end of said bar and having a downwardly dependingcutter blade positioned therein, bearing means on the lower end of saidbar above said tool holder, said means being rotatable with but nonreciprocable on said bar, a stripper member relatively slidable throughsaid tool holder and adjustably positioned in said bearing means, saidstripper member being normally disposed above and out of contact withthe material being out, said base being resilient and spaced from theframe whereby said frame and stripper foot may be pressed downwardly tobring said stripper foot into resilient contact with the material beingcut.

2. A cutter of the character described comprising a supporting framehaving a base member spaced from the frame adapted to slide overmaterial being cut, a plunger reciprocably mounted in said frame, a toolholder carried by the plunger for movement therewith, said tool holderhaving tool receiving means eccentric to said plunger, a stripper foot,means on said frame for normally supporting said stripper foot out ofcontact with the material being out, power means supported on the framefor reciprocating the plunger, said base member being resilient wherebysaid frame may be forced downwardly to bring said stripper foot intocontact with the material being cut.

3. A cutter of the character described comprising a supporting framehaving a resilient base adapted to slide over the material being cut, aplunger reciprocably mounted in said frame, a tool holder carried by theplunger for movement therewith, said tool holder having tool receivingmeans eccentric to said plunger, a stripper foot normally supported bysaid frame out of contact with the material being cut, power means forreciprocating said plunger, said base being connected at one end to saidframe and at its free end spaced from said frame, and means on saidframe whereby the frame may be conveniently forced downwardly toward thefree end of said resilient base member to bring said stripper foot intocontact with the material being cut.

4. A cutter of the character described comprising a supporting framehaving a base attached to and spaced therefrom adapted to slide onmaterial being cut, power means mounted on said frame, a plunger barrotatably supported on said power means and reciprocated thereby, a toolholder fixedly secured to the end of said bar and having a downwardlydepending cutter blade positioned therein, rotatable bearing means onsaid bar above said tool holder, a stripper member relatively slidablethrough said tool holder and fixedly positioned in said bearing means,said stripper member being out of contact with the material being cutbut engaging the material on the upstroke of the blade and stripping thematerial therefrom.

5. A cutter of the character described comprising a supporting framehaving a base attached thereto and adapted to slide on material beingcut, power means on said frame, a plunger arm fixedly and rotatablysupported on said power means and reciprocated thereby, a tool holderfixedly secured to the end of said bar and having a downwardly dependingcutter blade positioned therein, bearing means on the lower end of saidbar above said tool holder, said means being rotatable with but nonreciprocable on said bar, 'a stripper member relatively slidable'through said tool holder and adjustably positioned in said bearingmeans, said stripper member being normally disposed above and out ofcontact with the material being cut.

6. A cutter of the character described comp ris ing a supporting'framehaving a base attached thereto and spaced therefrom adapted to slide onthe material being cut, power means on said frame, a plunger barsupported on and actuated by said power means, a cutter carried by saidbar,

and spring means on said power means for reg:

means for regulating the stroke, of said cutter;

and outwardly extending bracket means on said frame cooperating withsaid base for supporting said cutter when tilted out of engagement withthe material being cut.

8. A cutter of the character described comprising a supporting framehaving a base attached thereto and spaced therefrom adapted to slide onthe material being cut, power means on said frame, a plunger barsupported on and actuated by said power means, a cutter carried by saidbar, spring means on said power means for regulating the stroke of saidcutter, and outwardly extending bracket means on said frame above saidcutter and base and cooperating with said base for supporting saidcutter when tilted out of engagement

